Fluoroplastics which are fabricable by melt flow at temperatures above their melting points have a wide range of utilities because of their chemical inertness and high melting temperature. These utilities could be broadened if such properties as room temperature toughness, high temperature physical properties such as heat distortion temperature and/or permeability could be improved. The use of additives in the fluoroplastic in an attempt to achieve such improvement suffers from one or more problems of incompatibility with the fluoroplastic, resulting in deterioration of desired properties, and difficulty in uniformly incorporating the additive into the fluoroplastic.